Example embodiments of the inventive concepts relate to three-dimensional semiconductor devices, and in particular, to connection structures of three-dimensional semiconductor devices and a methods of forming the same.
In semiconductor devices, increased integration is an important factor in realizing high-performance low-cost devices. Currently, in a two-dimensional memory semiconductor device or a planar memory semiconductor device, integration is largely affected by a technique of forming a fine pattern, because integration is often determined by an area that a unit memory cell occupies. However, since it may be difficult and/or expensive to form a fine pattern, it may be difficult to continue to increase integration of a two-dimensional memory semiconductor device.
To overcome such a limitation, three-dimensional memory devices (that is, including three-dimensionally arranged memory cells) have been proposed. Not only the memory cells but also interconnection lines (e.g., word lines or bit lines) are three-dimensionally arranged in the three-dimensional memory devices.